Counterfeit refrigerants, such as methyl chloride (R40) also known as chloromethane, have been found in refrigeration systems. R40 is toxic, flammable and reactive with aluminum. A reaction product of R40 with aluminum can include as trimethyl aluminum, which can burn spontaneously in the presence of air. There is therefore a need for a device to aid in the detection of counterfeit refrigerants, namely R40.